Valves for refrigeration apparatus having cooling and/or heating cycles



Oct. 19, 1965 R. M. HENDERSON 3,212,525

VALVES FOR REFRIGERATION APPARATUS HAVING COOLING AND/OR HEATING CYCLES Filed OCT,- 18, 1962 3 Sheets-Sheet l INVENTOR. RAY M. HENDERSON k A.. rM

A T TOR/V5 Y5 06b 19, 1965 R. M. HENDERSON 3,212,525

VALVES FOR REFRIGERATION APPARATUS HAVING COOLING AND/OR HEATING CYCLES Filed Oct. 18, 1962 3 Sheets-Sheet 3 RA V M. f/f/VfiffPJO/V INVENTOR.

ATTORA/EVJ United States Patent ()fi ice 3,212,525 VALVES FOR REFRIGERATION APPARATUS HAV- IN G COOLING AND/ OR HEATING CYCLES Ray M. Henderson, 139 E. Ridgewood Court, San Antonio, Tex.; Hallie Henderson, widow of said Ray M.

Henderson, deceased Filed Oct. 18, 1962, Ser. No. 231,487 6 Claims. (Cl. 137625.4)

This application is a continuation-in-part of my copending United States application Serial No. 137,362, filed September 11, 1961, and nOW Patent No. 3,088,293 and also Serial No. 36,200, filed June 15, 1960, and now Patent No. 3,074,249.

This invention relates to new and useful improvements in valves, and particularly valves for refrigeration apparatus having cooling and/ or heating cycles.

An object of this invention is to provide new and improved valve means responsive to fiuid pressure changes for controlling fluid flow therethrough.

Another object of this invention is to provide new and improved valve means adapted to be urged to one position by resilient means and to another position by fluid pressure.

A further object of this invention is to provide a new and improved valve means having a diaphragm controlled valve stem with a poppet valve thereon for regu lating gaseous refrigerant flow in a refrigeration system.

Still another object of this invention is to provide valve means particularly adapted to the regulation and control of the refrigerant pressure in the receiver of a refrigeration system during reverse cycle operation thereof in response to a condition of the refrigerant leaving the evaporator.

Yet another object is to provide a novel pressure differential valve for aiding reverse cycle or defrosting operations of a refrigeration system which is operable in response to changes in the temperature or pressure of the refrigerant leaving the evaporator to control the pressure at the inlet of the evaporator to thereby control the amount of liquid transmitted thereto through said inlet.

Other objects, features, and advantages of my invention will become apparent from the following description taken in connection with the accompanying drawings in which like reference numerals indicate like parts and in which:

FIG. 1 is a schematic view of a reverse cycle refrigeration system illustrating my invention;

FIG. 2 is a sectional view of the pressure regulating valve shown in FIG. 1 whereby the novel results of my invention are obtained;

FIG. 3 is a schematic view of another form of reverse cycle refrigeration system illustrating my invention;

FIG. 4 is a sectional view of the pressure regulating valve shown in FIG. 3;

FIG. 5 is a sectional view of another form of valve which is particularly adapted for use in reverse cycle refrigeration; and

FIG. 6 is a sectional view of still another form of valve which is especially suitable for use as a superheat valve in controlling refrigerant flow.

The condensing unit shown in FIG. 1 is of the water cooled type, but it could be of the air cooled type as illustrated in FIG. 3 or a combination of both without materially affecting the adaptations and functions of this invention and in view of this, the scope of my invention its not to be limited to any particular type of system.

In the conventional refrigeration system shown in FIG. 1 there is a compressor P, a condenser C, a receiver R, an evaporator E, an expansion valve X, and the usual connections therebetween, the functional operation of which is well known and understood. A water valve WV regulates the rate of supply of water to the condenser.

In combination with this conventional refrigeration system is shown a reverse cycle heating system designed for defrosting evaporator E, including a reversing valve RV, an expansion valve bypass including a check valve CV, a heat exchanger HX, a liquid diverting valve DV, a reverse acting water valve WV a liquid connection 10 known as a dip tube between the receiver and the condenser C, a bypass conduit connection 11 between the receiver and the conduit or condenser line CL which conmeets the condenser and the compressor in which is incorporated a pressure regulating valve PR, forming an important feature of my invention.

In this defrosting system, the reversing valve RV is of the conventional type and is operable by various means, preferably automatic, to reverse the flow of refrigerant in most parts of the system to thereby cause hot gas from the high side 12 of the compressor to be diverted through the suction line SL to the evaporator E where it will function as a heating medium to melt the frost which has accumulated during the refrigeration cycle of the system. The absorption of heat from this gas during this defrosting process will cause the gas to condense in the evaporator and become a liquid, which will flow by gravity to the bottom of the evaporator where it can pass through the check valve CV into the liquid line LL when the pressure conditions permit this valve to open. Simultaneously with this diversion of hot gas to the evaporator, the condenser line CL is connected through the reversing valve RV to the low side 13 of the compressor. This connection of the condenser to the low side will cause a pressure drop in the condenser and thereby convert the condenser into an evaporator. In this manner, the regular refrigeration evaporator will become a condenser during the defrosting operation and the regular condenser will become an evaporator, which will sometimes be referred to in this description and claims as a second evaporator. On such reverse cycle, the receiver actually functions as an evaporator since gaseous refrigerant is removed therefrom and therefore, the receiver is sometimes referred to as first evaporator means in the claims. It will be understood that a separate second evaporator, not used during the refrigeration cycle, might be used during the heating cycle if desired and condenser C cut out of the circuit.

When during defrosting the pressure in the second evaporator is reduced below the pressure in the receiver R, liquid refrigerant will flow from the receiver R through the dip tube 10 to the second evaporator and will be evaporated by the usual boiling process to absorb heat from the water or air, whichever the case may be, which is supplied to the condenser as a heat bearing agent for heat exchange with the refrigerant.

Pressure regulating means is provided to control release of gaseous refrigerant from receiver R and first releases excess pressure from the receiver to permit normal circulation of refrigerant to commence immediately after the system is placed on reverse cycle. The pressure regulating means then regulates the rate of flow of liquid refrigerant into the second evaporator in accordance with a condition of the refrigerant leaving the second evaporator. This release of refrigerant may be through a valved bypass line directly interconnecting the receiver and compressor or it may be through the condenser by the use of a dip tube in the receiver whose height may be controlled as in my copending application Serial No. 499,912, Patent No. 2,904,967.

My improved pressure regulating valve PR, as shown in detail in FIG. 2, is provided with a body 14 having a bore 15. Communicating with this bore is the condenser line CL, already referred to, and opposite thereto.

Patented Oct. 19, 1965 This bore is also connected to the reversing valve RV by a conduit 16. In the lower part of the bore is an adjustable valve seat 17 which is threaded into the body and adjustment is made possible by a stem 18 connected thereto and extending out of the lower end of the valve body, this stem being suitably packed, as shown, so that leakage cannot occur. Below the valve seat 17 there is provided a chamber 19 which has connected thereto the conduit 11 already referred to and connected to the top of the receiver R above any liquid line. Cooperating with the adjustable valve seat 17 is a check valve disc 20 for controlling the flow of refrigerant vapor past the valve seat 17 from the receiver to the bore 15 above the valve seat. The check valve disc 20 is acted upon by a pressure spring 21 interposed between the disc and the lower end of a plunger stem 22, which plunger stern extends upwardly through a perforated guide 23 at the top of the bore 15 and into a cap 24. A pressure responsive member such as a bellows 25 is positioned in the cap with its free end connected to the top or free end of the plunger stem and the other end of the plunger being connected to a closure plate 26 for the cap. The pressure responsive member 25 is exposed on one side to suction pressure through guide 23 and its movement is therefore influenced by the pressure of the gaseous refrigerant generated by condenser C.

The interior of the cap outside the bellows is connected by a capillary tube 27 to the bulb 28 attached to the condenser line CL as shown in FIG. 1. The movement of the plunger is controlled by the bellows 25 and the pressure in the cap and the movement of the plunger is further under the control of a compensating spring 29, said spring being interposed between the perforated guide 23 and a washer 30, welded or otherwise secured on the lower end of the plunger stem. Valve pressure spring 21 bears against the under side of washer 30. An open top cage 31 encloses spring 21 and washer 30. The bottom of the cage is secured to valve member 20. The top of the cage has an inturned flange 32 overlying washer 30. As soon as plunger 22 moves upward a sufficient distance to engage washer and flange 32, the valve member 20 is limited against further movement away from plunger 22 and further upward movement of plunger 22 will unseat valve member 20.

Again referring to FIG. 1, it will be noted that the reversing valve RV is associated with the suction line SL between the evaporator and the compressor P and the liquid line LL coming from the evaporator is connected to the diverting valve DV which has a conduit 33 connected to the coil 34 of the heat exchanger HX, which in turn is connected by a conduit 35 to the bottom of the receiver. Another line 36 from the diverting valve bypasses the heat exchanger. The water valves WV and WV control the flow of water from the water supply line 37 to the chamber surrounding the heat exchanger and through the condenser to the water discharge line 38. These water valves will be controlled by pressure in the condenser line CL, such being accomplished by conduits 39 and 40 leading to the control chambers of the Water valves. It will be noted that the water line between the heat exchanger HX .and the Water supply 37 is divided into two lines 41 and 42, with water valve WV in the line 41 and the water valve WV in the line 42. The chamber of the heat exchanger is connected to a usual coil in the condenser, not shown, by a conduit 43.

During the refrigeration cycle hot refrigerant gases in line CL will heat bulb 28 and the pressure within cap 24 will be such as to maintain the plunger 22 in its full down position. The valve disc 20 of the pressure regulating valve PR will remain closed and inoperative and such will have no effect in the system. This condition occurs because receiver pressure is transmitted to the lower side of disc 20 from the receiver R through conduit 11 and condenser pressure is transmitted to the top side of said disc by the direct connection to the condenser through the line CL. As a result, the high side of the compressor is effective on the top of the disc 20 and it is held seated.

When defrosting takes place by an operation of the reversing valve RV, generally automatically, the pressure in the condenser C will immediately be reduced by a pumping of gas therefrom by the low side of the compressor. The suction pressure of the codenser which now becomes a second evaporator, as previously indicated, will also immediately be reduced and assume a value below the pressure in the receiver. This causes the check valve disc 20 to be unseated and gas from the receiver is released into the condenser line CL, now connected to the low side of the compressor. The receiver pressure is consequently reduced, but controlled and limited by the functioning of the valve PR.

Thus, during the initial stage of defrosting when plunger 22 is in its full down position and the receiver pressure is necessarily greater than the suction pressure of the condenser acting as a second evaporator, the difference in pressure between the receiver and the second evaporator will become equal to the pressure exerted by the spring 21 on the check valve disc.

From experience it has been determined that the most efiicient operation of a condenser used as an evaporator is obtained by a flooded condition or by maintaining the liquid level in the condenser as near the top as possible without flooding over into the suction line and the compressor. This condition is maintained throughout the defrosting operation by the functioning of this valve.

It is common practice to lift liquid by providing adequate pressure behind the liquid to be lifted. In this operation, pressure of sufiicient force to lift the liquid refrigerant from the receiver to the desired height in the second evaporator is maintained above the liquid in the receiver, and it is a function of valve PR to so regulate this pressure that there will be sufficient pressure exerted on this liquid to lift it to the required height in the evaporator and to control this pressure to the extent that the liquid will not be forced out of the top of the evaporator into the compresser. It is another function of this valve to regulate the liquid level in proportion to the usable heat exchange surface of the evaporator to thereby control the super heated condition of the refrigerant during the evaporating process.

With respect to this, the spring 21 is important as it is of such compressive strength as to hold sufficient pressure in the receiver over the amount of pressure on top of the liquid in the condenser-evaporator, with stem 22 in full down position, to lift the liquid from the receiver to at least the point at which the bulb 28 is fastened in heat exchange relation with the evaporator suction or the point at which it is desired to stop the rise of liquid in the evaporator and maintain the liquid level. The power substance or the composition with which the bulb is charged is of a substance having a low boiling point, preferably the same refrigerant as used in the system. When the boiling liquid in the evaporator reaches the point of heat exchange relation with the bulb 28, heat is absorbed from the refrigerant in the bulb which will cause the temperature to be reduced and thereby reduce the pressure in the cap 24 which is exerted against the bellows 25. This reduction of pressure in the cap 24 will permit the pressure of the refrigerant, which is exerted against the inside of the bellows, to extend the bellows to thereby move the stem 22 upwardly to thereby reduce the pressure of the spring 21 against the top of the valve disc 20, which in turn will reduce the amount of pressure difference between the receiver pressure and the evaporator suction pressure. This reduction in pressure difference will cause the height of the liquid level in the second evaporator to be reduced and heat will no longer be taken from the bulb by refrigerant evaporating in line CL adjacent the bulb. The pressure in the power element will then increase by absorption of heat from the superheated gas in the suction line to again exert pressure on the bellows which is greater than the suction pressure, to thereby cause movement of the stem 22 downwardly and increase the pressure difference across valve 20 to cause the liquid level to rise in the condenser C which is serving as the second evaporator. In many instances pressure conditions will be such that, after excess pressure is released from the receiver and the pressure in bulb 28 reduced by giving off heat to the system refrigerant, the valve will regulate pressure with the cage flange 32 and washer 30 in abutting relationship. The chilling and heating action of the system refrigerant on bulb 28 will soon reach an equilibrium condition and valve 20 will maintain a differential which will hold the frost line at or just below bulb 28.

By this action it is apparent that the boiling liquid in the condenser C which is serving as the second evaporator will be limited in its passage through the condenser C serving as the second evaporator by the placement of the bulb 28, and that the boiling liquid will be held at the desired level in the condenser by regulation of the pressure difference between the receiver and the suction side of the condenser C serving as the second evaporator.

It is obvious that in various condensing units and their application the pressure difference required to lift the liquid to the proper height in the condenser acting as a second evaporator will vary, and therefore a variation of the spring pressure on the check valve disc will be necessary. To accomplish this variation of spring pressure the valve is provided with the adjustable seat 17. This valve seat may be raised or lowered to a limited extent. By moving the seat upwardly, the spring pressure of spring 21 will be increased to thereby increase the pressure difference, and by downward adjustment the spring pressure and pressure difference will be decreasd. This adjustment may also be used for adjusting the liquid level proportionately to the amount of usable heat exchange surface of the evaporator to thereby adjust and regulate the superheat of the expanded refrigerant.

As previously stated, an object of this invention is to control the liquid level or the supply of liquid to an evaporator by controlling or regulating the difference of pressure between one side of the evaporator and the other. This regulation of pressure is accomplished by the adjustment of spring pressure against the top of the valve disc of my improved pressure regulative valve PR. Both manual and thermostatic or automatic adjustment of the spring pressure has been provided, and therefore the improved valve may be adjusted manually to control the liquid level without the use or operation of the thermostatic means. Although manual adjustment might require more time and trouble, satisfactory results may be obtained.

In addition to the above described refrigerant evaporation regulating means, the water control system including two water control valves WV and WV and a heat exchanger HX are employed, as shown in FIG. 1. This water control system is illustrated and described in detail in my copending application Serial No. 397,309 referred to above and therefore need not be further described or discussed herein.

Referring now to FIGS. 3 and 4 this invention is illustrated in a system having an air cooled condenser C and heat exchanger HX and the liquid level in the condenser is controlled during the heating cycle without the use of bulb 28 by a pressure regulating valve PR Referring particularly to FIG. 4 of the valve PR is interposed in the conduit between the condenser C and compressor P and permits free fiow of refrigerant therethrough from inlet passageway 43 to outlet passageway 44. Bypass conduit 11 communicated with the inlet 43 and outlet 44 through passageway 45. Fluid flow through passageway 45 is controlled by a valve set 46 in passageway 45 and a cooperating valve member 47. Valve member 47 is free floating in passageway 45 and is guided in its movement to and from seated position by guide 48 which slidably engages the wall of passageway 45.

A plunger 49 is reciprocally mounted in the valve body 55 and biases the valve 47 toward its seat. A spring 50 is interposed between valve member 47 and plunger 49 and permits valve 47 to leave its seat when the system is placed on reverse cycle operation to relieve the excess pressure in receiver R.

The plunger 49 is secured to the free end 51 of bellows 52 and reciprocates with changes in suction pressure in line CL to vary the force exerted by spring 50. In this manner the differential between suction pressure and receiver pressure is varied with changes in suction pressure. Suction pressure reaches the inside of bellows 52 through plunger guide 53.

Adjustment of the force exerted by spring 50 is pro vided by a biasing means such as spring 54 mounted externally of valve body 55 in a cage 56. Cage 56 is secured to body 55 by through bolts 57 and held in spaced relationship therewith by cylindrical spacer 58 surrounding bellows 52. The force of spring 54 is exerted on the bellows through an end plate 59 which engages a stem 60 carried by bellows 52 and extending into cage 56. The force exerted by spring 54 may be selectively varied by rotating adjusting screw 61 which is threadedly carried in top end plate 62 for spring 54. Screw 61 has a shoulder 63 which engages thrust plate 64 and holds the screw 61 against longitudinal movement by the force of spring 54. Screw 61 also provides a stop for limiting expansion of the bellows during the cooling cycle.

During the cooling cycle of the system valve member 47 remains seated as the pressure in line CL is always greater than receiver pressure. As soon as the cycle of operation is reversed, hot gas condensing in evaporator E reduces evaporator pressure. Compressor P is also acting to reduce pressure in line CL. Under the influence of these two factors valve 47 will unseat and gas from receiver R will be bypassed until excess pressure is re moved permitting check valve CV to unseat and normal circulation to begin. Bellows 52 will begin to function to regulate suction pressure at this time. The force exerted by spring 54 will be adjusted to maintain a suction pressure which will maintain a desired liquid level in condenser C now functioning as a second evaporator. Suction pressure and the liquid level in condenser-evaporator C are directly related and an increase in the amount of liquid in condenser-evaporator C will cause an increase in suction pressure which will flex bellows 52 and reduce the force tending to hold valve member 47 on its seat. Valve member 47 will unseat and bleed off pressure from the receiver R which will permit the liquid level in condenser-evaporator C to fall. As this liquid level falls, suction pressure reduces and bellows 52 contracts and the force tending to seat valve member 47 increases and seats the valve member to prevent further reduction of receiver pressure.

Heater HX continuously provides sufficient heat to vaporize a small amount of refrigerant and provide more pressure in receiver R than necessary to support the desired level of refrigerant in condenser-evaporator C It will be understood that this heat could be provided by directing some of the condenser air over the receiver R or by any other desired means. In some instances it may be found that the system will develop sufficient pressure without special provisions for heat and if so heater HX may be omitted altogether.

While in both of the systems illustrated a single valve both relieves excess pressure in receiver R at the beginning of the heating cycle and thereafter regulates the differential between suction and receiver pressure it will be understood that these two functions might be accomplished by separate valves.

It will further be understood that relief of receiver pressure in response to a condition of the gaseous refrigerant generated in condenser-evaporator C may be through the condenser by utilizing the automatic dip tube shown in my application Serial No. 499,912 with plunger 22 or 49 connected to the free end of the dip tube bellows.

In FIG. 5, a modified valve is illustrated, which is preferably used as a heat control valve in a refrigeration apparatus having a heating and a cooling cycle, one form of which is illustrated in my copending US. application Serial No. 36,200. Such heat control valve is designated I-IV in FIG. and includes a body 130 which is divided into four chambers 130a, 130b, 130a and 130d. The chamber 130a is in fluid communication with a flow line 132 which extends from a source of gaseous refrigerant'such as the receiver R in FIG. 1.

The chamber 130b is in fluid communication with a flow line 134 which extends from the coil servingas the evaporator so as to therefore supply gaseous refrigerant to said chamber 13%. The chamber 1300 is in fluid communication with a flow line 124 which is ordinarily connected to a compressor or compressors such as indicated at P in FIG. 1.

The chamber 130d is separated from the chamber 130a by a flexible diaphragm 135 formed of a flexible metallic alloy of brass or other similar material, and such chamber 1300! is in fluid communication with the coil serving as the condenser through a tube 136.

The chambers 130a and 1301) are interconnected by a port 13% and the chambers 1301) and 130c are similarly interconnected by a port 130 The opening and closing of such ports 1302 and 130 is controlled by a valve member 138 which has valve heads 138a and 13812 formed thereon. The valve member 138 is also engaged by a spring or resilient member 139 at its lower end for applying an upward force to the valve member 138. The force of such spring 139 is suflicient to close the port 130a in the absence of any pressure in the chamber 130d, but when the pressure in the chamber 130d exceeds the pressure in the chamber 1300 by a predetermined amount which is sufficient to overcome the force of the spring 139, then the valve member 138 is moved downwardly to open the port 130a. The amount of force applied with the spring 139 may be increased or decreased by an adjusting member 140 which is preferably threaded in the housing or body 130 of the valve HV for movement upwardly and downwardly with respect to such body 130. Thus, as the adjusting member 140 is move-d upwardly, the spring 139 is compressed to cause it to exert a greater upward force on the valve member 138.

In the operation or use of the valve illustrated in FIG. 5, the pressure introduced through the tube or pipe 136 to the chamber 130d is normally from the high side of the refrigeration system and such pressure controls the opening and the closing of the valve member 138. Thus, when the pressure in the chamber 130d is insufficient to overcome the force of the spring 139, the valve head 138a is seated as illustrated in FIG. 5 so that there is flow only from the inlet tube 134, into the chamber 130b, through the passage 130 and then into the chamber 130a, and finally out through the outlet tube or pipe 124. When the high pressure of the gas in the chamber 130d is sufficient to force the stem of the valve 138 downwardly against the spring 139 to open the passage 130e, fluid is admitted from both the inlets 132 and 134 and such fluid is discharged out through the opening 124. If the pressure in the chamber 130d reaches an excessive amount, it is sufficient to close the valve head 1381) to thereby close the inlet flow from both of the inlet tubes 132 and 134.

When the valve HV is used for controlling the flow of refrigeration gases, the valve HV is set so that when the pressure in the line 136 from the coil serving as the condenser is extremely high because of the low heat requirement at the condenser coil, the valve member 138 is urged downwardly for the flow of the refrigerant from the line 132 and also the line 134 through the body 130 to the discharge tube or pipe 124. As explained in my copend- 8 ing application Serial No. 36,200, such valve thereby controls the level of the refrigerant in the evaporator coil through the high pressure side of the refrigeration circuit.

In FIG. 6, a still further modified valve SV is illustrat which is specifically adapted for use as a superheat valve in the refrigeration apparatus disclosed in said US. application Serial No. 36,200, although it has other uses. A flow line or pipe is connected to the body 152 of the valve SV. Normally, the line 150 is connected to a reversing valve such as indicated at RV in FIG. 1. The valve SV also has a second outlet line or pipe 132i). The valve SV is connected with the coil serving as the evaporator during the heating cycle by a flow line or pipe 151. The body or housing 152 of the valve SV has internal fluid chambers 152a, 152b, and 152C. The chambers 152a and 15212 are interconnected by a port 152d. A breather hole 152a is also provided as shown in FIG. 6.

The flow line 1321) is in communication with the fluid chamber 152a, and the flow lines 150, and 151 are in fluid communication with the fluid chamber 152b. A diaphragm 153 is positioned in the chamber 152s and is provided with air or other fluid under pressure above such diaphragm 153. The portion of the chamber 152a above the diaphragm 153 is in communication with a temperature bulb or other source of gaseous pressure through the tube 155a. When the pressure of the air or other fluid within the chamber 1520 reaches a suflicient amount to apply a downward force to the diaphragm 153 to over-come the upward force of the spring 157, the valve head 156a moves to the closed position shown in FIG. 6.

The valve element 156 is directly connected to the diaphragm 153 so that the pressure within the chamber 1520 controls the movement of the valve head 156a. The spring 157 acts against a flange 15612 to apply a predetermined force to the valve member 156 for urging same upwardly. Such spring force is adjustable by longitudinally moving an adjusting plate or screw member 158 relative to the body 152 in basically the same manner as heretofore described in connection with the adjusting member 140 (FIG. 5).

The spring pressure 157 is set so as to cause the passage or port 152d to open and close during the heating cycle in accordance with fluctuations in the temperature at the temperature bulb located at the upper level of the coil serving as the evaporator during the heating cycle, as disclosed in my copending application Serial No. 36,200.

When the pressure in the chamber 152a drops due to an absorbing of heat from the temperature control bulb, the pressure on the diaphragm 153 is reduced sufficiently to permit the spring 157 to move the valve head 156a towards the open position. Obviously, the reverse effect s obtained when the pressure in the chamber 152C is increased sufliciently to move the valve head 156a to the closed position shown in FIG. 6. When the valve head 156a is in the closed position shown in FIG. 6, the flow of the refrigerant is from the inlet line or pipe 151 through the valve chamber 152]; and out through the outlet line 150. When the valve head 156a is unseated so as to open the port 152d, a portion of the flow from the inlet line 151 is directed through the port 1520, the chamber 152a, and is discharged through the line 1321).

From the above it will be seen that all the objects of my invention have been accomplished. There has been provided a means and method for regulating flow of liquid refrigerant to the second evaporator during the heating cycle in response to a condition of the gaseous refrigerant generated by the second evaporator as well as novel valve means for employment in the system.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus and method.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcornbinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A valve for use in a refrigeration system, comprismg:

(a) a body having first and second interconnected inlet passageways and an outlet communicating with the passageways,

(b) a valve seat and a valve member cooperable therewith for controlling flow through the first passagey,

(c) said valve member urged toward its seat by a plunger mounted for reciprocation in the body,

((1) a pressure responsive member securred to the plunger and reciprocating the plunger upon move ment thereof,

(e) said pressure responsive member exposed on one side to the second passageway whereby movement of the pressure responsive member is influenced by pressure conditions in the second passageway, and

(f) means connected to the other side of said pressure responsive member from said first and second inlet passageways for varying the pressure of the gas acting on such other side.

2. The valve of claim 1, wherein the valve member is biased toward its seat by a resilient means interposed between the valve member and the plunger and wherein said body has passage means communicating said outlet with one of said inlet passageways when said valve member is seated and additional passage means for communicating both of said inlet passageways with said outlet when said valve member is unseated.

3. The valve of claim 1, wherein the other side of the pressure responsive member is exposed to a pressure vessel whose pressure is controlled by a temperature sensitive bulb,

4. A valve for controlling fluid flow in a refrigeration system, comprising:

(a) a body having first and second inlet openings and an outlet opening, said body having a valve seat disposed between said first and second inlet openings,

(b) a valve member reciprocal within said valve body and adapted to seat on said valve seat,

(0) a flow passageway in said valve body communicating sa'id first inlet opening with said outlet opening,

(d) a second passageway downstream of said valve seat and extending from said second inlet opening through the valve body to said outlet opening,

(e) fluid responsive means connected to said valve member for reciprocating same in response to fluid pressure changes acting thereon for controlling the flow of fluid to said outlet opening from said first inlet opening, and

(f) means connected to the other side of said pressure responsive member from said first and second inlet passageways for varying the pressure of the gas acting on such other side.

5. The structure set forth in claim 4, including a pair of valve heads on the valve member adapted to seat and open for controlling the flow of the fluid through the valve body.

6. The structure set forth in claim 4, including means for urging the valve member to a position closing flow through the passageway from the second inlet opening to the outlet opening.

References Cited by the Examiner UNITED STATES PATENTS 2,107,188 2/38 Ryder et a1. 137110 X 2,272,684 2/42 Vickers 137-501 X 2,449,123 9/48 Kimball et a1 l37-625 .4 2,986,899 6/6 1 Schenk et a1 1371'11 M. CARY NELSON, Primary Examiner. MILTON KAUFMAN, Examiner. 

1. A VALVE FOR USE IN A REFRIGERATION SYSTEM, COMPRISING: (A) A BODY HAVING FIRST AND SECOND INTERCONNECTED INLET PASSAGEWAYS AND AN OUTLET COMMUNICATING WITH THE PASSAGEWAYS, (B) A VALVE SEAT AND A VALVE MEMBER COOPERABLE THEREWITH FOR CONTROLLING FLOW THROUGH THE FIRST PASSAGEWAY, (C) SAID VALVE MEMBER URGED TOWARD ITS SEAT BY A PLUNGER MOUNTED FOR RECIPROCATION IN THE BODY, (D) A PRESSURE RESPONSIVE MEMBER SECURRED TO THE PLUNGER AND RECIPROCATING THE PLUNGER UPON MOVEMENT THEREOF, (E) SAID PRESSURE RESPONSIVE MEMBER EXPOSED ON ONE SIDE TO THE SECOND PASSAGEWAY WHEREBY MOVEMENT OF THE PRESSURE RESPONSIVE MEMBER IS INFLUENCED BY PRESSURE CONDITIONS IN THE SECOND PASSAGEWAY, AND (F) MEANS CONNECTED TO THE OTHER SIDE OF SAID PRESSURE RESPONSIVE MEMBER FROM SAID FIRST AND SECOND INLET PASSAGEWAYS FOR VARYING THE PRESSURE OF THE GAS ACTING ON SUCH OTHER SIDE. 